1. Field of the Invention
The present invention relates to a structure of a nailing machine. Especially, the present invention relates to a structure for mounting a spring (spiral spring) for a pusher of a nailing machine in which the spring for pushing the pusher in the direction of a nose section can be easily replaced. Further, the present invention relates to a structure of a guide for a pusher of a magazine of a nailing machine for guiding the pusher to push connected nails charged into the magazine in the longitudinal direction of the magazine.
2. Description of the Related Art
Conventionally, a spring (spiral spring) for pushing a pusher in the direction of a nose is fixed to a magazine with the following. A fixing pin is attached to a winding end section of the spring. In order to install the winding end of the spring into a magazine, a head portion of the fixing pin is protruded from an opening formed on a wall face of the magazine. The profile of the opening is formed being tapered in such a manner that the width on the side of a nose section is wide and the width on the side opposite to the nose section is narrow. Then, the magazine is moved to the side of the nose section so that the fixing pin is guided into the tapering section and the magazine is fixed to the nose section. In this way, the spring is fixed with being interposed between the nose section and the magazine.
However, when the above spring is used over a long period of time, it fatigues and the elasticity of the spring deteriorates and further the spring breaks. When the spring is replaced to solve the above problems, in order to release the fixing pin attached to the winding end of the spring, it is necessary to separate the magazine from the nose section. Accordingly, it takes time and labor to replace the spring.
As another aspect of a nailing machine, in general, the magazine of a nailing machine is provided for pushing and supplying connected nails, which are charged into the magazine, to a nose section side by a pusher. Therefore, the magazine has a guide path for guiding the connected nails and the pusher which pushes the connected nails onto the nose section side of the nailing machine. This guide path is a common guide means for guiding both the connected nails and the pusher. Therefore, when the connecting nails and the pusher are slid in the guide path, they move in the guide path while they are rubbing an inner wall face of the guide path.
The magazine is usually made of aluminum or aluminum alloy. Therefore, the abrasion resistance and mechanical strength of the magazine are relatively low. On the other hand, the connected nails and pusher, which are made of iron, are subjected to surface treatment. The cost of surface treatment of the connected nails is low, and the mechanical strength of the connected nails is not so high; however, since the pusher is frequently slid in the case of feeding and charging the nails, in order to prevent the pusher from wearing away, the pusher is subjected to quenching. Accordingly, since the surface hardness of the pusher is higher than that of the guide groove, when the pusher frequently slides in the guide groove, the surface of the guide groove is damaged. The thus caused damage becomes a resistance when the nails are fed, which could be a cause of failure of feeding the nails. Consequently, it is necessary to conduct an expensive surface treatment on the magazine.
The present invention has been accomplished to solve the above problems. That is, a first object of the present invention is to provide a structure for mounting a spring for a pusher of a nailing machine in which the spring for pushing the pusher can be easily replaced.
In order to attain the first object, the present invention provides a structure for mounting a spring for a pusher of a nailing machine in which a straight sheath-shaped magazine is connected with a nose section for driving a nail, and nails connected in a stick-shape are successively supplied into the nose section by a pusher arranged in the magazine, and the nails are driven from the nose section by a driver connected with a piston, wherein
a fixing pin is attached to a winding end section of a spring which is attached to the pusher and pushes the pusher in the direction of the nose section; a head portion of the fixing pin is protruded from an opening, the profile of which is tapered to the nose section side on the side of the magazine close to the nose section, and
a fixing plate, on which an engaging hole is formed, is engaged with the head portion of the fixing pin from the outside of the opening, and
the fixing pin is guided to the tapering section of the opening by moving the fixing plate in the direction of the nose section so as to fix the fixing plate to the nose section.
Further, the second object of the present invention is to provide a structure of a guide for a pusher of a magazine of a nailing machine characterized in that the surface of the guide path of the magazine is seldom damaged even if the magazine is not subjected to surface treatment, the cost of which is especially high.
In order to attain the second object, the present invention provides a structure of a guide for a pusher of a magazine of a nailing machine for guiding the pusher to push connected nails charged into the magazine toward a nose section of the nailing machine, wherein
the magazine has a guide groove for guiding a T-shaped top portion formed at an upper end of the pusher and for guiding head portions of the connected nails in an upper portion of a guide path of the pusher and the connected nails, and
a cover made of iron is attached to the inside of the guide groove, and
the wall thickness of a portion of the pusher passing through the nail guide path is smaller than the diameter of a nail axis portions.